Full Idea
Nor is it a sufficient explanation of the world to say just that all things were originally together. For things differ in matter. Indeed, why otherwise did an infinity of things come-to-be, and not just one?
Gist of Idea
It doesn't explain the world to say it was originally all one. How did it acquire diversity?
Source
Aristotle (Metaphysics [c.324 BCE], 1069b25)
Book Reference
Aristotle: 'Metaphysics', ed/tr. Lawson-Tancred,Hugh [Penguin 1998], p.358